The present invention relates to an information storage medium and an image generation device.
An image generation device (game system) that generates an image viewed from a virtual camera (given viewpoint) within an object space (virtual three-dimensional space) where an object (e.g., character) is disposed has been known, and is very popular as a means that allows the player to experience virtual reality.
For example, a related-art image generation device generates an image of a shooting game that allows the player to fire a bullet at an enemy character in an object space (three-dimensional space) using an input section.
JP-A-11-259686 disclose related-art technology.
Such a shooting game requires a reticle that allows the player to aim at a target object. A related-art shooting game is generally configured so that the reticle is disposed in a two-dimensional layer for displaying the score, ranking, and the like. In this case, an image obtained by superimposing an image projected onto a screen (projection plane) by perspective transformation and an image of a two-dimensional layer (in which the reticle and the like are disposed) is displayed (presented to the player).
However, the player may not be able to accurately determine the hit position when using the reticle disposed on a two-dimensional layer. In particular, the difference between the reticle position and the hit position may increase when the distance between the viewpoint and the hit position is long. Moreover, the operation of the shooting device and the movement of the reticle cannot be sufficiently synchronized when using the reticle disposed in a two-dimensional layer.
When implementing a shooting game that displays a stereoscopic image, the player may not be able to determine the hit position when using the reticle disposed on a two-dimensional layer, and the stereoscopic image may be impaired due to the two-dimensionally displayed reticle.
The inventors of the present application have been developing a shooting game that disposes a reticle within a virtual three-dimensional space, and moves a reticle corresponding to an operation performed by the player in order to enable accurate shooting. In such a shooting game, when a target object or a background object is present at the position of the reticle, the observability (visibility) is improved by displaying the reticle at (or on the front side of) the position of the object in the depth direction. When implementing a battle scene in which a number of target objects appear on the display screen, however, the target object disappears when the target object has been shot, and the reticle suddenly moves backward within the game space. This makes it difficult for the player to determine the reticle position.